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What Is a Heatsink? A Basic Definition


A heatsink is a piece of metal that sits on top of a computer chip such as a CPU and draws power away from components by letting it rise through a set of fins. By themselves, heatsinks are passive; they have no moving parts. However, in most cases--especially with desktop CPUs and GPUs--the heatsink is combined with a fan that blows the hot air away or a liquid cooling solution that carries the heat away through pipes.

A heatsink needs to make strong contact with the source of heat in order to maximize cooling. Heatsinks leverage a thermal conductor to move the heat into fins, which have larger surface areas and thus disperse the heat throughout the computer. Interestingly--and logically--a heatsink is a type of radiator.

This article is part of the Tom's Hardware Glossary.

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Scharon Harding

Scharon Harding is a Senior Editor at Tom's Hardware. She has a special affinity for gaming peripherals (especially monitors), laptops and virtual reality. Previously, Scharon covered business technology, including hardware, software, cyber security, cloud and other IT happenings, at Channelnomics, with bylines at CRN UK.